DTC C1295 Brake Lamp Switch Circuit Open. Chevrolet PJJ 2000

For 1990-2009 cars

### Circuit Description

The Stoplamp Switch is a normally open switch. When the brake pedal is depressed the EBCM senses battery voltage. This allows the EBCM to determine the state of the brake lamps. An open brake switch circuit will result in a modified ABS entrance criteria and possibly false settings of excessive wheel speed variation codes (C1225 thru C1228).

### Conditions for Running the DTC

This DTC can set anytime that the EBCM is powered.

### Conditions for Setting the DTC

The brake switch input voltage is between 1.87 volts and 5.28 volts for 2.0 seconds.

### Action Taken When the DTC Sets

• | A malfunction DTC is stored

• | ABS and ETS remains functional.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present and the scan tool Clear DTCs function is used.

• | The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

### Diagnostic Aids

• | The following are possible causes of this DTC:

- | The signal circuit of the brake switch is open.

- | The brake switch is misadjusted.

- | All of the brake lamps are open.

- | All of the brake lamp grounds are open.

- | The circuit has a wiring problem, terminal corrosion, or poor connections.

- | Loose or corroded EBCM ground.

- | An internal EBCM malfunction.

• | It is very important that a thorough inspection of the wiring and the connectors be performed. Failure to carefully and fully inspect the wiring and the connectors may result in a misdiagnosis, causing part replacement with a reappearance of the malfunction.

• | If an intermittent malfunction exists refer to Testing for Intermittent and Poor Connections in Wiring Systems.

### Test Description

The number below refers to the step number on the diagnostic table.

1. Tests the brake switch input circuit for an open or high resistance.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the ABS Diagnostic System Check? | -- | Go to Step 2 | Go to ABS Diagnostic System Check
2 | Press the brake pedal. Do the brake lamps turn ON? | -- | Go to Step 3 | Go to Exterior Lights System Check in Lighting Systems

3

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Press the brake pedal.
4. With a scan tool, observe the Brake Switch Status parameter in the ABS data list.

Does the scan tool display that the Brake Switch Status is ON?

--

Go to Testing for Intermittent and Poor Connections in Wiring Systems

Go to Step 4

4

1. Turn OFF the ignition.
2. Disconnect the brake switch connector.
3. Disconnect the EBCM connector.
4. Connect the J 39700 universal pinout box using the J39700-99 cable adapter to the EBCM harness connector only.
5. Test the brake switch input circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 5

5 | Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 7 | Go to Step 6
6 | Replace the EBCM. Refer to Electronic Brake Control Module Replacement. Did you complete the replacement? | -- | Go to Step 7 | --

7

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK